In Jainism, there is emphasis on self-discipline, mindfulness, and non-violence to all living beings. Eating before sunset is often recommended for practitioners (especially in the monastic code and in many layhousehold practices) for several simple reasons:

• Digestion and energy: Digestion is believed to be more efficient during the daytime. Eating earlier helps the body process food fully before night, which supports health and reduces discomfort.
• Minimizing harm to beings: Some Jain traditions avoid eating or handling food late in the day to reduce the chance of harming small insects or other life-forms that are active in the evening and night.
• Discipline and awareness: Finishing meals before evening fosters self-control, mindful eating, and a clearer mind for meditation and spiritual duties.
• Simplicity and routine: A daytime eating pattern aligns with the natural day-night cycle, making daily practice consistent and easier to maintain.

It's important to note that practices about meal timing can vary between Digambar and Shwetambar communities and between monks, nuns, and lay followers. If you want a precise rule for a particular tradition, I can explain that specific tradition's stance.